import java.math.BigDecimal;
import java.util.Scanner;
public class Test {
    public static void main(String[] args) {
        while(true){
            System.out.println("please enter your first number");
            Scanner scan = new Scanner(System.in);
            calculation calculation = new calculation();
            int x =0;
            int y =0;
            if (scan.hasNextInt()) {
                x = scan.nextInt();
                System.out.println("please enter your second number");
                y = scan.nextInt();
//        “使用scanner类获取x，y的值并且传给参数x，y”
                System.out.println("please choose your calculation");
                Scanner scanner1 = new Scanner(System.in);
                if (scanner1.hasNextLine()){
                    String method = scanner1.nextLine();
                    if (method.equals("add")){
                        int result = calculation.add(x, y);
                        System.out.println(result);
                    }
                    if (method.equals("subtract")) {
                        int result = calculation.subtract(x, y);
                        System.out.println(result);
                    }
                    if (method.equals("multiply")){

                        int result = calculation.multiply(x, y);
                        System.out.println(result);
                    }
                    if (method.equals("divide")){
                        if (y == 0){
                            System.out.println("0不能当除数");
                        }
                        else{double result =calculation.divide(x, y);
                            System.out.println(result);}
                    }
                    if (method.equals("involution")){
                        double result =calculation.involution(x, y);
                        System.out.println(result);
                    }
                    System.out.println("还要继续计算吗？请回答yes或no");
                    Scanner scanner2 = new Scanner(System.in);
                    if (scanner2.hasNextLine()){
                        String answer = scanner2.nextLine();
                        if (answer.equals("yes")){continue;}
                        if (answer.equals("no")){break;}
                    }}}}}}
